<?php
/**
 * Text Helper
 *
 * Text manipulations: Highlight, excerpt, truncate, strip of links, convert email addresses to mailto: links...
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.View.Helper
 * @since         CakePHP(tm) v 0.10.0.1076
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */

App::uses('AppHelper', 'View/Helper');
App::uses('Hash', 'Utility');

/**
 * Text helper library.
 *
 * Text manipulations: Highlight, excerpt, truncate, strip of links, convert email addresses to mailto: links...
 *
 * @package       Cake.View.Helper
 * @property      HtmlHelper $Html
 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html
 * @see String
*/
class TextHelper extends AppHelper {

	/**
	 * helpers
	 *
	 * @var array
	 */
	public $helpers = array('Html');

	/**
	 * An array of md5sums and their contents.
	 * Used when inserting links into text.
	 *
	 * @var array
	*/
	protected $_placeholders = array();

	/**
	 * String utility instance
	 *
	 * @var stdClass
	*/
	protected $_engine;

	/**
	 * Constructor
	 *
	 * ### Settings:
	 *
	 * - `engine` Class name to use to replace String functionality.
	 *            The class needs to be placed in the `Utility` directory.
	 *
	 * @param View $View the view object the helper is attached to.
	 * @param array $settings Settings array Settings array
	 * @throws CakeException when the engine class could not be found.
	 */
	public function __construct(View $View, $settings = array()) {
		$settings = Hash::merge(array('engine' => 'String'), $settings);
		parent::__construct($View, $settings);
		list($plugin, $engineClass) = pluginSplit($settings['engine'], true);
		App::uses($engineClass, $plugin . 'Utility');
		if (class_exists($engineClass)) {
			$this->_engine = new $engineClass($settings);
		} else {
			throw new CakeException(__d('cake_dev', '%s could not be found', $engineClass));
		}
	}

	/**
	 * Call methods from String utility class
	 *
	 * @param string $method Method to call.
	 * @param array $params Parameters to pass to method.
	 * @return mixed Whatever is returned by called method, or false on failure
	 */
	public function __call($method, $params) {
		return call_user_func_array(array($this->_engine, $method), $params);
	}

	/**
	 * Adds links (<a href=....) to a given text, by finding text that begins with
	 * strings like http:// and ftp://.
	 *
	 * ### Options
	 *
	 * - `escape` Control HTML escaping of input. Defaults to true.
	 *
	 * @param string $text Text
	 * @param array $options Array of HTML options, and options listed above.
	 * @return string The text with links
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoLinkUrls
	 */
	public function autoLinkUrls($text, $options = array()) {
		$this->_placeholders = array();
		$options += array('escape' => true);

		$pattern = '#(?<!href="|src="|">)((?:https?|ftp|nntp)://[\p{L}0-9.\-_:]+(?:[/?][^\s<]*)?)#ui';
		$text = preg_replace_callback(
				$pattern,
				array(&$this, '_insertPlaceHolder'),
				$text
		);
		$text = preg_replace_callback(
				'#(?<!href="|">)(?<!\b[[:punct:]])(?<!http://|https://|ftp://|nntp://)www.[^\n\%\ <]+[^<\n\%\,\.\ <](?<!\))#i',
				array(&$this, '_insertPlaceHolder'),
				$text
		);
		if ($options['escape']) {
			$text = h($text);
		}
		return $this->_linkUrls($text, $options);
	}

	/**
	 * Saves the placeholder for a string, for later use. This gets around double
	 * escaping content in URL's.
	 *
	 * @param array $matches An array of regexp matches.
	 * @return string Replaced values.
	 */
	protected function _insertPlaceHolder($matches) {
		$key = md5($matches[0]);
		$this->_placeholders[$key] = $matches[0];
		return $key;
	}

	/**
	 * Replace placeholders with links.
	 *
	 * @param string $text The text to operate on.
	 * @param array $htmlOptions The options for the generated links.
	 * @return string The text with links inserted.
	 */
	protected function _linkUrls($text, $htmlOptions) {
		$replace = array();
		foreach ($this->_placeholders as $hash => $url) {
			$link = $url;
			if (!preg_match('#^[a-z]+\://#', $url)) {
				$url = 'http://' . $url;
			}
			$replace[$hash] = $this->Html->link($link, $url, $htmlOptions);
		}
		return strtr($text, $replace);
	}

	/**
	 * Links email addresses
	 *
	 * @param string $text The text to operate on
	 * @param array $options An array of options to use for the HTML.
	 * @return string
	 * @see TextHelper::autoLinkEmails()
	 */
	protected function _linkEmails($text, $options) {
		$replace = array();
		foreach ($this->_placeholders as $hash => $url) {
			$replace[$hash] = $this->Html->link($url, 'mailto:' . $url, $options);
		}
		return strtr($text, $replace);
	}

	/**
	 * Adds email links (<a href="mailto:....) to a given text.
	 *
	 * ### Options
	 *
	 * - `escape` Control HTML escaping of input. Defaults to true.
	 *
	 * @param string $text Text
	 * @param array $options Array of HTML options, and options listed above.
	 * @return string The text with links
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoLinkEmails
	 */
	public function autoLinkEmails($text, $options = array()) {
		$options += array('escape' => true);
		$this->_placeholders = array();

		$atom = '[\p{L}0-9!#$%&\'*+\/=?^_`{|}~-]';
		$text = preg_replace_callback(
				'/(?<=\s|^|\(|\>|\;)(' . $atom . '*(?:\.' . $atom . '+)*@[\p{L}0-9-]+(?:\.[\p{L}0-9-]+)+)/ui',
				array(&$this, '_insertPlaceholder'),
				$text
		);
		if ($options['escape']) {
			$text = h($text);
		}
		return $this->_linkEmails($text, $options);
	}

	/**
	 * Convert all links and email addresses to HTML links.
	 *
	 * ### Options
	 *
	 * - `escape` Control HTML escaping of input. Defaults to true.
	 *
	 * @param string $text Text
	 * @param array $options Array of HTML options, and options listed above.
	 * @return string The text with links
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoLink
	 */
	public function autoLink($text, $options = array()) {
		$text = $this->autoLinkUrls($text, $options);
		return $this->autoLinkEmails($text, array_merge($options, array('escape' => false)));
	}

	/**
	 * Highlights a given phrase in a text. You can specify any expression in highlighter that
	 * may include the \1 expression to include the $phrase found.
	 *
	 * @param string $text Text to search the phrase in
	 * @param string $phrase The phrase that will be searched
	 * @param array $options An array of html attributes and options.
	 * @return string The highlighted text
	 * @see String::highlight()
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::highlight
	 */
	public function highlight($text, $phrase, $options = array()) {
		return $this->_engine->highlight($text, $phrase, $options);
	}

	/**
	 * Formats paragraphs around given text for all line breaks
	 *  <br /> added for single line return
	 *  <p> added for double line return
	 *
	 * @param string $text Text
	 * @return string The text with proper <p> and <br /> tags
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoParagraph
	 */
	public function autoParagraph($text) {
		if (trim($text) !== '') {
			$text = preg_replace('|<br[^>]*>\s*<br[^>]*>|i', "\n\n", $text . "\n");
			$text = preg_replace("/\n\n+/", "\n\n", str_replace(array("\r\n", "\r"), "\n", $text));
			$texts = preg_split('/\n\s*\n/', $text, -1, PREG_SPLIT_NO_EMPTY);
			$text = '';
			foreach ($texts as $txt) {
				$text .= '<p>' . nl2br(trim($txt, "\n")) . "</p>\n";
			}
			$text = preg_replace('|<p>\s*</p>|', '', $text);
		}
		return $text;
	}

	/**
	 * Strips given text of all links (<a href=....)
	 *
	 * @param string $text Text
	 * @return string The text without links
	 * @see String::stripLinks()
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::stripLinks
	 */
	public function stripLinks($text) {
		return $this->_engine->stripLinks($text);
	}

	/**
	 * Truncates text.
	 *
	 * Cuts a string to the length of $length and replaces the last characters
	 * with the ellipsis if the text is longer than length.
	 *
	 * ### Options:
	 *
	 * - `ellipsis` Will be used as Ending and appended to the trimmed string (`ending` is deprecated)
	 * - `exact` If false, $text will not be cut mid-word
	 * - `html` If true, HTML tags would be handled correctly
	 *
	 * @param string $text String to truncate.
	 * @param int $length Length of returned string, including ellipsis.
	 * @param array $options An array of html attributes and options.
	 * @return string Trimmed string.
	 * @see String::truncate()
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::truncate
	 */
	public function truncate($text, $length = 100, $options = array()) {
		return $this->_engine->truncate($text, $length, $options);
	}

	/**
	 * Truncates text starting from the end.
	 *
	 * Cuts a string to the length of $length and replaces the first characters
	 * with the ellipsis if the text is longer than length.
	 *
	 * ### Options:
	 *
	 * - `ellipsis` Will be used as Beginning and prepended to the trimmed string
	 * - `exact` If false, $text will not be cut mid-word
	 *
	 * @param string $text String to truncate.
	 * @param int $length Length of returned string, including ellipsis.
	 * @param array $options An array of html attributes and options.
	 * @return string Trimmed string.
	 * @see String::tail()
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::tail
	 */
	public function tail($text, $length = 100, $options = array()) {
		return $this->_engine->tail($text, $length, $options);
	}

	/**
	 * Extracts an excerpt from the text surrounding the phrase with a number of characters on each side
	 * determined by radius.
	 *
	 * @param string $text String to search the phrase in
	 * @param string $phrase Phrase that will be searched for
	 * @param int $radius The amount of characters that will be returned on each side of the founded phrase
	 * @param string $ending Ending that will be appended
	 * @return string Modified string
	 * @see String::excerpt()
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::excerpt
	 */
	public function excerpt($text, $phrase, $radius = 100, $ending = '...') {
		return $this->_engine->excerpt($text, $phrase, $radius, $ending);
	}

	/**
	 * Creates a comma separated list where the last two items are joined with 'and', forming natural English
	 *
	 * @param array $list The list to be joined
	 * @param string $and The word used to join the last and second last items together with. Defaults to 'and'
	 * @param string $separator The separator used to join all the other items together. Defaults to ', '
	 * @return string The glued together string.
	 * @see String::toList()
	 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::toList
	 */
	public function toList($list, $and = 'and', $separator = ', ') {
		return $this->_engine->toList($list, $and, $separator);
	}

}
